Here's how:
* Buster Brown's violent nature: Buster Brown is a vicious dog who attacks Byron and Kenny, representing the unpredictable and brutal nature of racial violence. His actions highlight the constant threat that Black people face in the South.
* The "nigger" slur: The children are told to call Buster Brown "nigger" when they are around white people, showing how even a dog can be used to dehumanize and belittle Black people.
* The contrast with the friendly dogs in Birmingham: The Watsons encounter friendly dogs in Birmingham, showcasing the kindness and warmth of Black communities. This contrasts sharply with the aggressive nature of Buster Brown, highlighting the stark difference in how Black people are treated in the North and the South.
In essence, Buster Brown serves as a foreshadowing device, foreshadowing the violence and prejudice that the Watson family will encounter in Birmingham. His presence introduces a chilling element of fear and foreshadows the dangers that await them in the South.